a) Field of the Invention
This invention relates to a buckle stay for supporting a buckle in a seatbelt system to be mounted on a vehicle body.
b) Description of the Related Art
A seat of a vehicle such as an automotive vehicle is conventionally provided with a seatbelt system to ensure safety of an occupant. In this seatbelt system, a webbing which serves to protect the occupant in the seat is connected at an end thereof to a retractor arranged in a lower part of a center pillar and is fixed at an opposite end thereof on an anchor plate arranged on a lower part of the center pillar. A tongue plate is slidably arranged on the webbing. Fastening or unfastening of the webbing is effected by latching or unlatching the tongue plate in or from a buckle supported by a buckle stay which is arranged on a floor of the vehicle with the seat located between the buckle stay and the retractor.
The buckle stay is generally provided with an anchor fixedly fastened on the vehicle and also with a buckle stay member fixed at an end thereof on the anchor and connected at an opposite end thereof with the buckle of the seatbelt system.
Buckle stays of various designs have been proposed as such buckle stays to date, for example, including a buckle stay with a buckle stay member formed by providing a wire or cable (hereinafter collectively called xe2x80x9ca wirexe2x80x9d), bending the wire such that it is curved at a central portion thereof into a loop, fixing the loop portion on a buckle base of a buckle, inserting opposite ends of the wire into holes formed in the anchor, and then crimping the anchor around the holes to fix the opposite ends of the wire.
For example, a buckle stay disclosed in U.S. Pat. No. 4,915,451 is provided with a wire bent in a loop at a central portion thereof and also with an attachment plate for fixedly fastening the wire on a vehicle body. The wire is fixed on a buckle on a side of the loop, and opposite end portions of the wire have been fixedly secured to the attachment plate by inserting the opposite end portions into channels of the attachment plate, respectively, and then crimping the attachment plate around the channels to hold the opposite end portions in place.
To assemble the buckle stay disclosed in U.S. Pat. No. 4,915,451, the opposite end portions of the wire, that is, two wires are inserted together into their corresponding channels formed in the attachment plate, and the attachment plate is then crimped around the channels. However, insertion of two wires into their corresponding channels at the same time is however more difficult than insertion of a single wire into a channel. Further, fixing of two wires by crimping at the same time is more difficult than fixing of a single wire by crimping.
When two wires are fixed together by crimping, the wires themselves have such stiffness that, when the buckle stay is mounted on a vehicle, the wires themselves can be readily bent in both longitudinal and lateral (transverse) directions of the vehicle. When mounted on the vehicle, the stability of the buckle stay is not very high accordingly. To improve the fitness to an occupant, it is preferably for the stay member to be resistant to bending in the longitudinal direction of the vehicle but to be easily bendable in the lateral direction of the vehicle. If it is intended to increase the stiffness of a buckle stay in the longitudinal direction, use of a high-stiffness wire is desired. However, this also leads to high stiffness in the lateral direction.
The buckle stay of the above-described construction is also required to have highly-reliable strength at the crimped portion where the wires are held together by crimping, because loads concentrate in their entirety on the crimped portions.
To obtain the attachment plate, complex pressing work is needed, thereby requiring labor.
With the foregoing background in view, the present invention has as an object thereof the provision of a seatbelt system provided with a buckle stay which requires simpler assembling steps, which can disperse to plural locations a load applied on a buckle stay member and which can also enhance reliability in strength.
To achieve the above-described object, the present invention provides a seatbelt system provided with a buckle stay for supporting a buckle, wherein the buckle stay comprises:
an anchor for being fixedly fastened on a vehicle body, said anchor being provided with a plurality of anchor portions; and
a buckle stay member fixed at an end thereof on the anchor and connected at an opposite end thereof with the buckle, said buckle stay member being branched at the one end thereof into a like plural number of end portions, and said branched end portions being fixedly secured by the anchor portions, respectively.
To achieve the above-described object, the present invention also provides a seatbelt system provided with a buckle stay for supporting a buckle, wherein the buckle stay comprises:
an anchor for being fixedly fastened on a vehicle body, said anchor being formed of a pipe-shaped member and comprising:
a bent portion for surrounding a member to be used to fixedly fasten the buckle stay on the vehicle body, and
a pair of extensions extending out from the bent portion and terminating at free ends thereof in anchor portions such that the bent portion, the paired extensions and the anchor portions, in combination, have a substantially U-shaped form; and
a buckle stay member formed of a wire in a substantially U-shaped form such that the buckle stay member is fixedly secured by the anchor portions at free end portions of the wire, respectively, and is connected with the buckle at a central curved portion of the wire.
In each of the buckle stays of the above-described constructions, the buckle stay member is fixed at plural portions thereof on the anchor so that a load applied to the buckle stay, for example, in the event of a vehicular collision or the like can be dispersed to the plural portions. Described specifically, the load can be borne at the respective branched end portions, thereby making it possible to avoid concentration of the load at any particular portion and hence to enhance reliability in strength.
Further, the buckle stay in which the buckle stay member is formed of the wire in the substantially U-shaped form and is fixed at the free end portions is characterized in that its stiffness in the lateral direction of a vehicle is not high although its stiffness in the longitudinal direction of the vehicle is high because two wire portions are highly resistant to compression forces.